Quadruplex neutral relay



UNITED STATES ATENT FFICE.

CHARLES D. I-IASKINS, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE WESTERNELECTRIC COMPANY, OF CHICAGO, ILLINOIS.

QUAD Ru FLEX N EUTRAL. RELAY.

SPECIFICATION forming part of Letters Patent No. 523,119, dated July 17,1894.

Application filed .April3,1893- Serial No- 1 (N m l-l To 00% whom it mayconcern.-

Be it known that I, CHARLES D. HASKINS, a citizen of the United States,residing at Brooklyn, in the county of Kings and State of New York,haveinvented a certain new and useful Improvement in Quadruplex NeutralRelays (Case No. 11,) of which the following is a full,

clear, concise, and exact description, reference being had to theaccompanying drawings, forming a part of this specification.

My invention relates to telegraph relays, and more particularly toneutral relays used in connection with quadruplex telegraphy. Its objectis to avoid the false signal which is incident to the quadruplexapparatus heretofore employed.

In quadruplex systems of telegraphy one line is provided at each endwith two receiving and two transmitting instruments, with circuits soarranged that four messages may be simultaneously transmitted over thesingle line-that is to say, four operators are required at each end ofthe line, two for sending and two for receiving. Considering theapparatus at one end of the line, We have two receiving instruments, onea polarized relay, and one a neutral relay. The transmitting instrumentsconsist, one of a double current transmitter or pole-changer, and theother of a single current transmitter or continuity-circuit-preservingkey. The receiving instruments are wound dilferentially in the wellknown way, so that current sent through their coils by the transmittinginstrument at the same end of the line will not operate either of them.This is accomplished in brief by sending current in branches through thedifferential windings, one branch going to ground, and the other branchto line, the electrostatic capacity and resistance of the line beingequalized by a condenser and rheostat, in the well known way. In theworking of quadruplex systems of this class a well known defect exists.This defect is a false signal which is caused at the neutral relay whenthe polarity of its current is changed by the double current transmitterat the distant end during the time that the armature of said neutralrelay should be affected only by the operation of the single currenttransmitter. This false signal results from the fact that the operatorof the continuity-circuit-preserving key at the transmitting end has nocontrol over the polarity changing transmitter,

and while the former may be sending a dash,

for instance, the operator of the pole changing transmitter may reversethe direction of current on the line and thus the direction of currentthrough the neutral relay. This would occur while the neutral relayarmature is drawn up against the poles of the magnet, and results in asudden change of polarity in the electro-magnet. The soft iron armaturemomentarily retaining the polarity of the magnetism previously inducedtherein by the electro-magnet, there is a momentary repulsion betweenthe armature and the poles of the electro-magnet which kicks thearmature away and makes the false signal already mentioned. This falsesignal has been heretofore prevented by various devices, especiallydesigned for this purpose, as is shown, for example, in Moffatt andBlakeney No. 351,993 of November 2, 1886; Jones, No. 360,528 of April 5,1887, and Charles D. Haskins, No. 405,211, of June 11, 1889, and No.455,398 of July '7, 1891, all for quadruplex telegraphy.

My present invention is intended to obviate such false signals, and itconsists, briefly, in providing a neutral relay with an armature whichis surrounded by practically the same electrical influence as surroundsthe electromagnet with which it works. In other words, the armature ofmy invention is preferably an exact duplicate of the electro magnet,both as to form, size and magnetic properties and electricalsurroundings. Thus whatever electrical influences actuate theelectro-magnet, equally actuate the armature, and any change of polarityin one is simultaneously accompanied by a change of polarity in theother. Hence, reversals of direction of the current never cause arepulsion even of momentary duration between the armature and theelectro-magnet.

While it is true that there is an instant in which there is noattraction between the armature and electro-magnet, I have found inpractice that the inertia of the armature lever is sufficient to resistthe retractile force of the spring for a time long enough to hold thearmature in its place for this brief instant.

My invention will be more readily understood by reference to theaccompanying drawings, in which-- Figure 1 is a front elevation of arelay of my invention. Fig. 2 isarear elevation. Fig. 3 is a sectionalview on line 03-00 of Fig. 1.

Like parts are referred to by similar letters of reference in the threeviews.

The magnets a Z) are mounted within a frame 0, which may be fastenedupon a suitable base (1. The magnets are of the usual differentiallywound type. The cores of the magnets consist of rods 6 f which projectbeyond the magnets and the frame 0. The core c of the upper magnet a isheld stationary by being splined to the drum of the spool by a spline g,or in any other suitable manner. The lower core f of magnet b is allowedfreedom of mo tion within the spool. This core is preferably mounted atits ends upon pivot screws 7t 7t, which in turn are mounted upon theupright standards ii. By means of this method of mounting the core f iscapable of rotary movement. This rotary movement, however, is limited bythe lever 76 which is screwed upon one end of the coref. The upper endof this lever 7a is provided with contact points Z Z and is limited inits movement by the contact screws m m in the usual manner. Point Z iscaused to rest normally upon contact screw m by means of a retraetilespring It which is attached to the lever 7a. The retractile force ofthis spring is controlled by means of the thumb-screw p, to the shank ofwhich is at tached the other end of the spring n by means of the cord q.

Extensions 7") of the magnet core 6 are provided, which are adapted toattract extensions 8 s of the armature core f, which are preferablysymmetrically placed with relation to the extensions of the magnet corec. This construction practically results in the production of twoelectro-magnets, one of which, with its core, is fixed, while the coreof the other is adapted to have a rocking movement.

It should be noted that while the ideal condition for a relay embodyingmy invention is one in which the armature is an exact duplicate as toelectrical surroundings and magnetic properties, nevertheless, thiscondition maybe departed from and yet good practical .results secured. Ido not wish to limit 1nyself to a construction in which there is exactidentity of surrounding conditions in the two, nor do I wish to limitmyself to the precise mode of embodying my invention herein shown anddescribed, as it is obvious the same result may be secured bymodifications of details which will readily suggest themselves. Nor do Iwish to limit myself to the special application of myinveution hereinshown, as many different uses for it may be found. For

example, two electro-magnets so related to sea-its each other that theyare adapted to OKGl'l] the same reciprocal influence upon each other,substantially as I have described, maybe advantageously used in anycircuit upon which an alternating current is used, as by means of thisarrangement the momentary repulsion between the armature and the pole ofthe elec tro-magnet of the ordinary construction, is obviated; but

What I claim as new, and desire to secure by Letters Patent, is-

1. In a neutral relay, the combination with an electro-magnet providedwith a core, of an armature adapted to be affected by saidelectro-magnet and serving as the core of a helix connected in the samecircuit with the helix of said electromagnet, said helices beingequivalent as to magnetic inductive influence upon their respectivecores, said cores being equivalent as to magnetic susceptibility;whereby reversal of the current flowing in said helices causes themagnetization of said cores to fall, change sign and rise in unison,substantially as described.

2. In a neutral relay, the combination with an electromagnet providedwith a stationary core, of a pivotally mounted armature adapted to beaffected by said electro-magnet and serving as the core of a stationaryhelix connected in the same circuit with the helix of saidelectro-magnet, said helices being equivalent as to magnetic inductiveinfluence upon their respective cores, said cores being equivalent as tomagnetic susceptibility; whereby reversal of the current flowing in saidhelices causes the magnetization of said cores to fall, change sign,andrise in unison,substantially as described.

8. in a neutral relay, the combination with an eleetro-magnet providedwith a core carrying an arm at right angles to the axis thereof, of anarmature adapted to be affected by said electro-magnet and serving asthe core of a stationary helix connected in the same circuit with thehelix of said electromagnet, said armature core being pivoted to rotateabout its axis and carrying an arm at right angles to its axis adaptedto engage the arm of the core of said electronnagnet, said helices beingequivalent as to magnetic inductive influence upon their respectivecores, said cores being equivalent as to magnetic susceptibility;whereby reversal of the current flowing in said helices causes themagnetization of said cores to fall, change sign, and rise in unison,substantially as described.

In witness whereof I hereunto subscribe my name this 20th day of March,A. l). 1893.

CHARLES D. HASKINS.

Witnesses:

Guonon MOMAIION, Guess-n L. Canon.

